MHT CET202526 Apr 2025Morning ShiftPhysicsSemiconductorsActual
The material used for solar cell should have band gap
Options
- Aequal to zero.
- Bless than 1.0 ~eV (non-zero).
- Cmore than 1.8 eV.
- Dbetween 1.0 ~eV and 1.8 ~eV .
Correct answer
D. between 1.0 ~eV and 1.8 ~eV .
Step-by-step solution
The efficiency of a solar cell is highly dependent on the semiconductor's band gap, E_g . Photons with E_ photon E_g are absorbed but lose excess energy as heat through thermalization. A small band gap (e.g., 1.8 eV) limits absorption to high-energy photons, wasting much of the solar spectrum. The optimal range for single-junction solar cells is 1.0 eV to 1.8 eV, balancing absorption and voltage efficiency. Silicon, with E_g 1.12 eV, is widely used due to its placement within this range. Therefore, the material sho